The following dissertation, Alternative Abstractions: Art and Science in Twentieth-Century Los Angeles investigates how the histories of astronomy and modern physics impacted the production of abstract artwork in Southern California. In the artistic practices of Helen Lundeberg, Bettina Brendel, Mary Corse, and Frederick Eversley, histories of observational cosmology, quantum mechanics, astrophysics, and aerospace engineering both converge with and complicate existing art historical narratives of abstract painting and sculpture in Los Angeles. By examining Lundeberg, Brendel, Corse, and Eversley’s artistic explorations of space, light, and energy alongside the scientific sources influencing their work, these case studies reveal how theories and technologies derived from subfields of modern physics prompted artists to consider the subjectivity of human vision, experience, and knowledge. Through the project’s interdisciplinary approach, abstraction emerges as a process of mediation between the realms of the conceptual and the material central to theoretical debates in both modern art and science over the twentieth century. Synthesizing insights from histories of art, science, and technology in the United States and Europe, this research sheds new light on the prevalence of scientifically inflected modes of artistic abstraction in Southern California.